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Long–Term Effect of VVI Pacing on Atrial and Ventricular Function in Patients with Sick Sinus Syndrome
Author(s) -
PAXINOS GEORGE,
KATRITSIS DEMOSTHENES,
KAKOUROS STAVROS,
TOUTOUZAS PAVLOS,
CAMM A. JOHN
Publication year - 1998
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1998.tb00130.x
Subject(s) - medicine , ejection fraction , cardiology , atrial fibrillation , sick sinus syndrome , sinus rhythm , stroke volume , diastole , prospective cohort study , heart failure , blood pressure
We conducted a prospective, 6–month echocardiographic study on the effect of WI pacing on left atrial and ventricular function and dimensions in patients with sick sinus syndrome. Thirty nine patients (23 women and 16 men, aged 71.7 ± 9.2 years; 30 in sinus rhythm and 9 in atrial fibrillation) who had a WI pacemaker implanted because of sick sinus syndrome were recruited in the study. In 26 patients who presented with and remained in sinus rhythm, paced left ventricular ejection fraction and stroke volume were significantly decreased (71.4%± 11.8% to 67.0%± 13.6%, and 73.9 ± 29.0 cm 3 to 66.3 ±21.1 cm 3 , respectively, P < 0.001 for both), whereas the paced diastolic dimension of the left atrium was significantly increased (3.2 ± 0.7 cm to 3.7 ± 0.9 cm, P < 0.001) at 6 months as compared with preimplantation. In nine patients with atrial fibrillation at implantation, paced left ventricular ejection fraction at follow–up was significantly decreased (67.7%±10.1% to 64.2%± 10.6%, P = 0.003), but paced stroke volume and left atrial diastolic dimension were not significantly changed (75.1 ± 25.6 cm 3 to 79.0 ± 22.7 cm 3 , and 4.3 ±1.2 cm to 4.6 ±1.5 cm, P = NS for both) at follow–up. Cessation of pacing and restoration of sinus rhythm in 21 patients at follow–up did not result in any significant change of ejection fraction (67.5%± 10.2% to 67.6%± 9.7%, P = NS) whereas stroke volume was increased (59.1 ± 19.6 cm 3 to 69.1 ± 22.3 cm 3 , P < 0.0001) in comparison with paced values. However, compared with preimplantation values, ejection fraction was significantly decreased (70.4%± 10.0% to 67.6%± 9.7%, P = 0.001), whereas stroke volume was not significantly changed (68.4 ± 22.3 cm 3 to 69.1 ± 22.3 cm 3 , P = NS) during sinus rhythm at follow–up. In 14 of those patients, discontinuation of pacing resulted in a significant increase of left atrial fractional shortening (8.1 %± 1.7% to 20.1 %± 4.3%, P < 0.001) and significant increase of left atrial diastolic dimension compared with paced and preimplantation levels (3.8 ± 0.7 cm vs 3.6 ± 0.7 cm and 3.0 ± 0.5 cm, respectively, P < 0.001). Long–term WI pacing in patients with sick sinus syndrome results in increase of the left ventricular end–systolic dimension and permanent reduction of the left ventricular ejection fraction. In the left atrium, WI pacing causes an immediate reduction of the fractional shortening as well as long–term increase of the diastolic dimension.